Abstract: Power amplifier (PA), regardless of the process used for the manufacturing of its devices, suffers from a nonlinear output capacitance that has significant impact on various aspects of the PA performance. This output capacitance is dependent on the large output voltage swing. Accordingly a compensation capacitance is added at the output of the PA that has a behavior that is inverse respective of the output voltage of that of the output capacitance of the PA. Connecting the compensation capacitor in parallel to the PA output capacitance, results in a total capacitance that is the sum of the output capacitance and its compensation capacitance. The total output capacitance is therefore essentially stable throughout the output voltage swing.

Abstract: According to one embodiment, a class-C power amplifier includes an amplifying element whose power supply voltage is expressed as Vdc and whose maximum current is expressed as Imax, a conduction angle ?o of the amplifying element being less than ?(rad), and load impedance of a fundamental wave being expressed as Z1=R1+j·X1 and load impedance of a 2nd harmonic being expressed as Z2=R2+j·X2 which are observed from a dependent current source of an equivalent circuit of the amplifying element, wherein a relationship between variables X1 and R1 is set to ?R1<=X1<=R1, variable R1 is set to R1=Vdc/Imax·?·{1?cos(?o/2)}/{?o/2?sin(?o)/2}, and variable X2/X1 is set to X2/X1=?{?o/2?sin(?o)/2}/{sin(?/2)?sin(1.5·?o)/3}, or each of the variables is set thereto so as to become equal substantially.

Abstract: A power amplifier is configured to generate impedances at harmonic frequencies such that the power amplifier operates in a class C mode in a low output amplitude range and in a class F or inverse F mode in a high output amplitude range. Related methods of operation are also discussed.

Abstract: A radio frequency (RF) amplifier structure provides highly efficient RF signal amplification across a wide bandwidth, when implemented in both inverting and non-inverting Doherty designs, by employing matching impedance transform circuits that comprise a low pass multiple section inductance-capacitance circuit and that provides impedance matching between the output of an amplifier device and a power combiner, wherein the output matching impedance transform circuit has approximately an odd multiple of 90 electrical degrees over the RF amplifier structure's frequency range of operation, and adjustable phase delay circuits that route an amplified RF signal to the power combiner and that are controllably adjusted based on a frequency of an RF input signal over an operating frequency range of the RF amplifier structure.

Abstract: A directional coupler utilizes an inductive element of a power amplifier and a coupled conductive element. The inductive element of the power amplifier is a functioning element within the power amplifier and at least part of the inductive element of the power amplifier is disposed in a multi-layer substrate. At least part of the coupled conductive element is disposed in the multi-layer substrate. The coupled conductive element is configured to be inductively coupled to the inductive element of the power amplifier such that the coupled conductive element carries a first RF signal that is representative of a second RF signal within the inductive element of the power amplifier.

Abstract: A radio frequency system includes a power amplifier that outputs a radio frequency signal to a matching network via a transmission line between the power amplifier and the matching network. A sensor monitors the radio frequency signal and generates first sensor signals based on the radio frequency signal. A distortion module determines a first distortion value according to at least one of (i) a sinusoidal function of the first sensor signals and (ii) a cross-correlation function of the first sensor signals. A first correction circuit (i) generates a first impedance tuning value based on the first distortion value and a first predetermined value, and (ii) provides feedforward control of impedance matching performed within the matching network including outputting the first impedance tuning value to one of the power amplifier and the matching network.

Abstract: An apparatus and method for a switched capacitor architecture for multi-band Doherty power amplifiers are provided. The apparatus is for amplifying Radio Frequency (RF) signals, and the apparatus includes a multi-band Power Amplifier (PA) including a plurality of input matching circuits including switchable capacitors, and a plurality of output matching circuits including the switchable capacitors, wherein the multi-band PA is tunable to more than one RF frequency band.

Abstract: The present invention relates to a power amplifier unit (30, 40, 50, 60a-60d, 70) comprising a power amplifier element (31, 41, 51, 71) and a matching unit (32, 42, 52, 72). The unit comprises an impedance matched MicroElectroMechanicalSystem (MEMS) switch element (33, 43, 53, 73) between said power amplifier element (31, 41, 51, 71) and said matching unit (32, 42, 52, 72).

Abstract: For use in a wireless network, a tunable power amplifier circuit includes a power amplifier transistor and a plurality of laminate MEMS (microelectromechanical system) capacitors coupled to the power amplifier transistor. The laminate MEMS capacitors are arranged in a tunable matching network and configured to provide a matching impedance for the power amplifier transistor. In some embodiments, the laminate MEMS capacitors are arranged in a binary array.

Abstract: Systems and methods are provided for facilitating variable precision tuning of an amplifier circuit. In accordance with one aspect of the present disclosure, the system includes an amplifier having multiple tuning stages to set the gain of the amplifier to discrete gain levels. In particular embodiments, the tuning stages are connected in series and each of the tuning stages includes a resistor connected in parallel to a switch, which can be disengaged to cause the amplifier to set the gain to an adjacent gain level. In certain embodiments, the difference in gain between each adjacent one of the plurality of gain levels is more at higher gain levels than at lower gain levels.

Abstract: A variable impedance device includes a passive tuner that includes at least one variable component, which is controllable to apply a variable impedance value to an input signal of the passive tuner. A low noise amplifier is configured to supply the input signal to the passive tuner by amplifying an input RF (radio frequency) signal.

Abstract: A signal processing apparatus includes: clip detector means that detects presence/absence of a clipped part with a deformed waveform in each of N audio signals output from N microphones (where N is an integer equal to or greater than 2) based on a dynamic range of a circuit; and interpolation means that treats an audio signal in the N audio signals which has the clipped part detected by the clip detector means as an interpolation target, and other audio signals as non-interpolation targets, and interpolates the waveform of the clipped part of the interpolation target using the waveform of at least one audio signal in the non-interpolation targets.

Abstract: A class AB amplifier includes a first inductor having a first terminal in communication with a voltage source terminal. A first transistor has a drain terminal in communication with a second terminal of the first inductor. A second transistor has a source terminal in communication with a source terminal of the first transistor. A second inductor has a first terminal in communication with a drain terminal of the second transistor and a second terminal in communication with a reference potential. The drain terminals of the first transistor and the second transistor are capacitively coupled together.

Abstract: A radio front end includes a transformer and an adjustable load. The transformer includes a first winding and a second winding, wherein the first winding is operably coupled to an antenna and the second winding coupled to at least one of a power amplifier and a low noise amplifier. The adjustable load is operably coupled to the second winding, wherein the adjustable load provides a first impedance based on a first impedance selection signal when the radio front end is in a transmit mode and provides a second impedance based on a second impedance selection signal when the radio front end is in a receive module such that impedance at the first winding is substantially similar in the transmit mode and in the receive mode.

Abstract: A peaking circuit for adjusting peaking of a high-frequency signal, comprises: a first inductor; a second inductor which is electromagnetically coupled with the first inductor; a signal input section which receives an input signal; a transistor which adjusts electric current passing through the second inductor according to the input signal inputted via the signal input section; and a signal output section which outputs a signal whose peaking has been adjusted by the first inductor. Mutual inductance of the electromagnetically coupled first and second inductors is changed by the adjustment of the electric current passing through the second inductor, according to the input signal inputted via the signal input section, with the use of the transistor, thereby adjusting the peaking of signal waveform of electric current passing through the first inductor, and the signal subjected to the peaking adjustment is outputted from the signal output section.

Abstract: A CMOS amplifier with integrated tunable band-pass function, a tunable active resistor structure, a method of amplifying an input signal and a method of fabricating an amplifier. The tunable active resistor structure comprises two symmetrically cross-coupled transistors.

Abstract: A method and apparatus are provided for using an automatic BW adjustment circuit to automatically adjust the bandwidth of an electronic amplifier based on the amplitude of a signal that is output from a variable gain amplifier or of one or more variable gain stages that follow the amplifier. By automatically adjusting the bandwidth of the electronic amplifier based on the amplitude of the signal, bandwidth enhancement can be provided while also preventing, or at least reducing, peaking of the frequency response of the electronic amplifier.

Abstract: An integrated power amplifier includes a divider and a combiner. The integrated power amplifier also includes two or more amplifiers. Each of the amplifier input terminals is electrically coupled to a divider output terminal and each of the amplifier output terminals is electrically coupled to a combiner input terminal. At least one power sensor is configured to provide a power amplifier performance metric. The divider and the combiner include a plurality of actuators. Each actuator has at least one actuator control terminal which is configured to provide an actuator setting. The actuators are configured via the actuator control terminals to optimize the power amplifier performance metric. Methods to simulate the operation of a self-healing power amplifier and a process for the operation of a self-healing circuit are also described.

Abstract: Methods and systems for a single-ended input low noise amplifier (LNA) with differential output are disclosed and may include configuring the LNA and/or a balun on a chip for single-ended or differential mode, which may function as a load for the LNA. A frequency response and gain of the LNA may be configured via switched capacitors and resistors, which may include CMOS transistors. A transition frequency, and thus impedance matching and matching network gain, may be tuned via configurable gate-source capacitors. A received signal may be filtered via a surface acoustical wave (SAW) filter. The LNA may be impedance matched with an input device via the transition frequency tuning and off chip inductors and/or capacitors. The LNA may be configured for single-ended or differential input mode via switches outside of a signal path to the LNA and reverse isolation may be enabled via a cascode device.

Abstract: A calibration unit calibrates a power amplifier load impedance to achieve a nominal amplifier load impedance after the connection of one or more external elements, e.g., antenna, to improve the accuracy and effectiveness of output power calibration. The calibration unit comprises an adaptive impedance unit and a controller. The adaptive impedance unit includes first and second variable impedance elements connected between the amplifier and the external load, e.g., antenna. The controller independently calibrates the imaginary and real parts of the load impedance by respectively selecting first and second calibration values for the first and second variable impedance elements based on a reference voltage. More particularly, the controller selects calibration values for the first and second variable impedance elements from a plurality of impedance values based on a comparison between a reference voltage and the calibrated voltages produced at the output of the power amplifier responsive to the impedance values.

Abstract: A radio front end includes a transformer and an adjustable load. The transformer includes a first winding and a second winding, wherein the first winding is operably coupled to an antenna and the second winding coupled to at least one of a power amplifier and a low noise amplifier. The adjustable load is operably coupled to the second winding, wherein the adjustable load provides a first impedance based on a first impedance selection signal when the radio front end is in a transmit mode and provides a second impedance based on a second impedance selection signal when the radio front end is in a receive module such that impedance at the first winding is substantially similar in the transmit mode and in the receive mode.

Abstract: A wideband tuneable low noise amplifier that is capable of receiving signals over a wide range of frequencies, providing tuneable filtering to remove out of band interferer signals, and providing variable gain for a wide range of frequencies. To accommodate variable gain, the low noise amplifier has an amplifier stage comprising two gain stages, and the relationship between the gain stages is controlled responsive to changes in the voltage gain of an input stage. Linearity monitoring combined with Q-enhance may be employed to increase performance at low signal levels.

Abstract: Low noise amplifier circuit. The low noise amplifier circuit includes an amplifier that amplifies an input to provide an output. The amplifier is coupled to an input terminal. The circuit also includes a device in a cascode connection with the amplifier. The circuit further includes a tuning circuit coupled to the device to phase shift the output. Further, the circuit includes a feedback circuit that is responsive to a phase-shifted output to enhance gain of the amplifier. The feedback circuit is coupled to the tuning circuit and the amplifier.

Abstract: There is disclosed a variable-gain amplifier circuit that operates on a low voltage, exhibits low distortion, provides a wide range of variation, and is suitable for use in a low-power-consumption wireless communication system. The variable-gain amplifier circuit is configured so that a variable-load circuit, which includes three reactance function elements and provides a wide range of impedance variation, is connected to a conductor circuit whose output terminal generates a positive-phase output current proportional to conductance with respect to an input voltage.

Abstract: For use in a wireless network, a tunable power amplifier circuit includes a power amplifier transistor and a plurality of laminate MEMS (microelectromechanical system) capacitors coupled to the power amplifier transistor. The laminate MEMS capacitors are arranged in a tunable matching network and configured to provide a matching impedance for the power amplifier transistor. In some embodiments, the laminate MEMS capacitors are arranged in a binary array.

Abstract: Embodiments of circuits and systems for a harmonic tuning network coupled with a radio frequency (RF) push-pull power amplifier to terminate both second- and third-harmonic energies are disclosed. Other embodiments may also be described and claimed.

Abstract: An apparatus and method for amplifying a transmission signals in multiple modes and multiple bands. The apparatus includes a tunable power amplifying module adapted to receive a plurality of signal types comprising multiple modes and multiple bands. The tunable power amplifying module includes a first and second power amplifier stages and a number of tunable matching networks configured to optimize an impedance value based on the mode and band of the signal to be amplified.

Abstract: According to one embodiment, there is a semiconductor device including a first active element, a second active element connected in parallel with the first active element, and a first stabilization circuit connected between a gate of the first active element and a gate of the second active element and configured with a parallel circuit of a gate bypass resistor, a gate bypass capacitor, and a gate bypass inductor, the first stabilization circuit having a resonant frequency equal to an odd mode resonant frequency.

Abstract: Various apparatuses and methods for amplifying an FM signal in a segmented linear power amplifier are disclosed herein. For example, some embodiments provide an apparatus including a signal input, a signal output, and an output driver connected between the signal input and the signal output. The output driver includes a number of driver segments connected in parallel, each having an input connected to the signal input and each having an output. The output driver also includes a number of series capacitors, each associated with one of the driver segments. The series capacitors are each connected between the output of its associated driver segment and the signal output. The output driver also includes a number of shunt capacitors, each associated with one of the driver segments having an associated series capacitor. The shunt capacitors are each connected between the output of their associated driver segment and a ground.

Abstract: According to some embodiments, an apparatus may comprise an amplifier, wherein the amplifier comprises: an output stage formed of a positive output terminal providing a positive output voltage and a negative output terminal providing a negative output voltage; a load tank coupled in parallel with the output stage and configured to filter signals received at the amplifier; and a negative resistance block coupled in parallel with the output stage and the load tank.

Abstract: A high-frequency input circuit. The input circuit includes an input node, a bond pad, and a signal conversion resistor coupled in series between the input node and the bond pad to convert substantially all of a signal voltage at the input node to a signal current at the bond pad.

Abstract: A low noise amplifier (LNA) includes an LNA input that receives a signal from an antenna. The LNA also includes an internal amplifier with an input that is coupled to the LNA input, as well as an internal filter with an input coupled to the output of the internal amplifier and an output coupled to the input of the internal amplifier. The coupling of the output of the internal filter to the input of the internal amplifier provides feedback to the input of the internal amplifier. The internal filter is configured to pass signals within a frequency range through to the output of the internal filter.

Abstract: A front-end circuit with coherent tunable filters is provided. The circuit includes a first filter, an amplifier, and a second filter. The amplifier is coupled to the first filter, and the second filter is coupled to the amplifier. Furthermore, the amplifier is placed between the first and second filters. The first filter has a first tunable intermediate frequency, and is used to filter a received signal. The amplifier is used to amplify the output of the first filter. The second filter has a second tunable intermediate frequency, and is used to filter the output of the amplifier. The first and second intermediate frequencies have a coherent-tuning relation with each other.

Abstract: A receiver includes a feedback low noise amplifier (LNA). The feedback LNA has an LNA gain and includes an LNA input configured to receive a signal from an antenna and an LNA output configured to output an amplified voltage signal. The receiver also includes a resistive element, having a resistance, coupled to the LNA output and configured to convert the amplified voltage signal into a current. The receiver also includes a current commuting mixer coupled to the resistive element and configured to receive the current from the resistive element, where the current output by the resistive element is determined at least in part by the amplified voltage signal and the resistance of the resistive element.

Abstract: A distortion compensation system minimizes distortion in an audio system by monitoring a supply voltage and adjusting a clipping threshold and/or compression knee. An adjustable gain circuit controls the gain of the audio signal according whether the audio signal exceeds a variable threshold. The variable threshold is adjusted within a threshold range based on the supply voltage. Distortion due to clipping of the audio signal is minimized while available power at any given time is maximized.

Abstract: According to one embodiment, there is a semiconductor device including a first active element, a second active element connected in parallel with the first active element, and a first stabilization circuit connected between a gate of the first active element and a gate of the second active element and configured with a parallel circuit of a gate bypass resistor, a gate bypass capacitor, and a gate bypass inductor, the first stabilization circuit having a resonant frequency equal to an odd mode resonant frequency.

Abstract: CMOS power amplifiers (PAs) are disclosed having one or more integrated one-time programming (OTP) memories that are utilized to control at least in part operation of the CMOS PAs. The integrated OTP memories within the CMOS power amplifiers (PAs) allow adjustments, such as one-time factory trimming, of CMOS PA integrated circuits to optimize or improve performance. With this capability, for example, the tuning and biasing of stages within a multi-stage amplifier within a CMOS PA can be measured during factory test and adjusted by setting one or more bits in the OTP memories, as desired. Further, the operation of other circuitry within the PA can also be controlled at least in part with parameter settings stored in the OTP memories.

Abstract: An output terminal 6 is provided at the connecting point 5 between the collector terminal of a transistor 1 and an open-ended stub 4 by connecting the open-ended stub 4 to the collector terminal of the transistor 1, the open-ended stub 4 having a line length equal to a quarter of the wavelength of a signal of frequency 2N·F0 or 2N times the oscillation frequency F0. In addition, an output terminal 9 is provided at a connecting point 8 located at a distance equal to a quarter of the wavelength of a signal of oscillation frequency F0 from the end of an open-ended stub 7 by connecting the open-ended stub 7 to the base terminal of the transistor 1, the open-ended stub 7 having a line length longer than a quarter of the wavelength of the signal of oscillation frequency F0.

Abstract: A transistor is provided to amplify a high frequency signal. A gate/base of the transistor receives the high frequency input signal. A variable capacitor is connected between the gate and a source/between the base and an emitter of the transistor. A variable inductor is connected with the source/the emitter of the transistor.

Abstract: The present invention relates to a tunable filter device for providing a tunable band pass characteristics for the receive path of a multi-band front-end module. According to the invention is proposed, a distributed, wide-band amplifier with a low-frequency cut-off and a high-frequency cut-off in combination with a LCR network, of which wide-band amplifier the DC blocking capacitors define the low-frequency cut-off of the filter device, whilst the high-frequency cut-off is determined by the cut-off frequency of the artificial input and output transmission lines of the LCR network. In one embodiment, additional capacitors are coupled in parallel to the DC blocking capacitors of the LCR network, switchable by MOS transistors as switching elements. Accordingly, in a certain embodiment it is proposed to allow tuning of the low- and the high-frequency cut-off by programming with a digital control command.

Abstract: This amplifier (10) for radio frequency signals comprises a circuit adapted to amplify the signals within a first range of frequency (19) and is characterized in that said circuit is also adapted to simultaneously attenuate the signals within a second range of frequency (18).

Abstract: The present invention addresses the problem to extend the dynamic power range where the amplifier operates linearly for a full input amplitude swing with improved efficiency. According to the present invention, the above presented problem is solved by changing the delivered power to the load by changing the value of the load and still keeping the amplifier in its linear condition. The invention enables the amplifier to maintain high efficiency over a wider power range.

Abstract: Techniques for designing an efficient power amplifier are described. In one aspect, multiple single unit instance class-D power amplifiers with coupled outputs are utilized to increase efficiency and reduce quantization noise. In another aspect, multiple groups of single unit instance class-D power amplifiers are coupled at the outputs thereof with each group of power amplifiers configured to resonate at unique frequency. This results in increased efficiency and reduction of quantization noise at multiple frequencies bands.

Abstract: An RF amplifier circuit includes a MOSFET connected to an RF output of the circuit via an impedance matching network including an inductor and a tuning capacitor connected in parallel with the inductor and the MOSFET. DC voltage is applied to the MOSFET via a series path through a radio frequency choke and the inductor of the impedance matching network.

Abstract: A first FET is inserted in a series position between a signal input terminal and a signal output terminal, while second and third FETs are inserted in a shunt position respectively between the signal input terminal and a ground terminal and between the signal output terminal and a ground terminal. First and second reference voltage terminals and a control terminal are provided. A first reference voltage and a control voltage are applied to the first FET, while a second reference voltage and a control voltage are applied respectively to the second and third FETs, so that the first, second, and third FETs serve as variable resistors. As such, a gain control circuit is constructed. Further, a first resistor is provided in parallel to the first FET, while second and third resistors are provided respectively in series to the second and third FETs.

Abstract: A switched capacitor system with output glitch reduction step charges the switched capacitor by switching it to a first voltage level in a first phase, to an intermediate voltage level of a pre-charge node in a pre-charge phase and to the voltage level of the output node of the amplifier stage in a settling phase; the pre-charge node can be implemented at the input of the amplifier stage, the output of a preceding stage or at any other pre-existing suitable node in the amplifier system.

Abstract: This document discloses, among other things, a front end circuit having a selectable center frequency. The center frequency is selected based on a control signal proportional to a phase difference between a reference frequency and an amplifier output. A resonant frequency of a tank circuit coupled to the amplifier is tuned using the control signal.

Abstract: An adaptively tuned RF power amplifier includes at least one power amplifier stage that has one or more active elements. A tunable output network is coupled to the power amplifier stage and includes one or more adjustable reactive elements. A mismatch detector detects a tuning mismatch based, at least in part, on one or more signals present within the tunable output network, and supplies one or more mismatch signals indicative of a detected tuning mismatch. A tuning controller, responsive to the one or more mismatch signals, controls one or more of the one or more adjustable reactive elements in the tunable output network so as to control the detected mismatch.

Abstract: Various embodiments are disclosed relating to Q-enhancement cells. According to an example embodiment, a circuit may include an inductor with a quality factor (Q), and a Q-enhancement cell coupled to the inductor. The Q-enhancement cell may include a current source having a variable bias current slope. Stability may, for example, be improved by providing a variable or programmable bias current slope for the Q-enhancement cell. In another example embodiment, a Q-enhancement cell may be used to compensate for Q degradation due to one or more switched capacitors in a circuit. The switched capacitors may be used, for example, for channel or frequency selection for the circuit. In another example embodiment, a Q-enhancement cell may be used to compensate for Q degradation caused by a transmission line.

Abstract: Apparatus and method for reducing the current consumption and increasing the efficiency of a MIMO system, consisting of one or more RF power amplifiers (PAs) and that is required to provide a desired total output power level. An individual output power level which is a portion of the total output power level is determined for each PA. The load, connected to the output stage of each PA, is dynamically or statically tuned to essentially match the output impedance of its output stage, such that its dynamic or static RF load line has a slope that corresponds to the impedance required to provide this portion. Whenever a smaller output power is desired in response to reduction in the input signal to MIMO system, a reduced portion is determined for each PA and the load is further tuned, such that the dynamic/static RF load line has a slope that causes each PA to essentially remain in saturation while providing the reduced portion.